Apparatus for detecting inflammable gases in air.



A. PHILIP 6L L. J. STEELE. APPARATUS PCR DBTEGTING INPLMMBLE GASES INAm. V Arrlonxon rmzn un'. o, 1901. I "068.v V' j Patented Spt. 22, 1908.4 A a suma-snm' 1.

mloruy.

A. PHILIP & L. J. STEELE. APPARATUS Pon DETEGTING INYLAMMABLE .GASES INAIR.

APPLIGATIOI( FILED SEPT. 9. 1901.

Patented Sept 22, 1908.

'a sums-sans? 2.-

Kfm?

A. PHILIP a L. JSTBEL, PPABTUS FOB DETECTING INFLMMABLE GASES IN AIBAPPLIUATIO FILED SEZ'T. 9. 19.01.

Patented sept` 22,1908.

3 BHBETl-SHEET I.

Immun..

@mmf

yi'JNITEiD STATES PATENT OFFICE.

APPARATUS ron nn'rnc'rmo To all whom it mai concern.'

Be it known t at we, ARNOLD PHILIP, B. Sc., chemist, and Louis JOHNSTEELE, M. I. E. E., electrical engineer, subjects of the King of GreatBritain, both lresiding at His Majest "s dockyard, Portsmouth, in thecounty of l anipshire, England, have invent ed new and useful Apparatusfor Detecti Intlainmahle Gases in Air, of which the if lowing is aspecification.

This invention relates to an improved apparatus for the detection ofcombusti-b e gases or vapors.

The apparatus comprises a detector of the type in w ich the activity ofa catalytic substance is utilized to 'put the indicator in aetion-a'system of pipes extending from this detector to an' desired parts ofthe space to be protecte and a pump of suitable type to draw air throughthese pipesand su pply it to the detector.

Various improvements are also made in details of the apparatus. Forexample the electrical devices cm loyed in the detector are so arranvedthat t ie actuation of the apparatus shall` be attended with a minimumof sparking and moreover these devices are protected by casings and soforth which prevent access to parts where a circuit may be broken exceptafter the opening of a switch control l'l those parts.

mEIinor details are designed'to prevent as far as possible injury to theapparatus or to indicate when the apparatus has been put out of order.

The invention is illustrated in the accompaying drawin rs in whichigure1 isa iagram of the electrical 'cir-V cuits employed lin one form of theapparatus. Fig. 2 shows an external view of that apparatus, Fig. 3 is adetail thereof, and Fig. 4 a Vsli htly modified form.

n the form shwn in Figs. 1, 2 and 3 a Wire a of sensitive metal 'isari-an .ed in parallel with the resistance a in an e ectrical circuitsupplied with power from 'the nia-ins b. In cach branch of the circuitis inserted a lamp c or other indicator which serves to show byinspection whether an break has taken place in that branch ofythecircuit in which it is placed, and also a solenoid d or d' both of thesesolcnoids acting on one pivoted armature e. Two main indicating lampsf,g of which f is red and g white, are

munged in series betweemthe saineor other Spe'cication of'LettersPatent.

Application ledeptomber 9, 1901. Serial No. WLM

ARNOLD. PHILIP AND LOUIS I. STEELE, OF PORTSMOUTH, ENGLAND.

LE GASES IN All.

lamps f, g, is 'oined to a contact on the armature e While t e otherterminals come tu oontacts h, 7c against which the contact on thettpencea sept; sa, isos. y

supplynans. The common terminal ofthe tromagnets with their pivotedarmature aie preferably arran ed in a'casing. suspended -en springs orthe li e as illustrated so that the apparatus is not likely to operatewhen jarred or tilted. The in tubes l, l' secured by clips within a c mas shown in Fig. 4 so that if either of them should break they may bereplaced without delay-b 'insertion of a spare tube. Air is supplie tothe casing throu h the tube n and passes through the tube -ente at theholes'z' and leaving by the holes a ound the tube l. lhe action of thisty e o apparatus is well understood. Initi wires a, a are inclosed'-thelresistances of the wires a, a' are so b anced that when the normalstream of air is passing the solenoids d, d exert a force which drawsthe armature e to the !eft against contact h so that the redvlamp f isshort cirouited.4

When owing to the presence of infiammable i gas in the air passingthrough the apparatus the wire a becomes more highly heated itsresistance increases and the'current through the solenoid d thereforediminishes, the armature eis drawn -to the right .against contact 7c,short circuiting the lamp g and breaking the short circuit across theamp f.-

As shown in Fig. 2 the air is supplied to the apparatus by a p um odriven by a motor p, the air being drawn om all parts of the space to beguarded by tubes q. lBefore y entering the casing containing the -tubesl, l the air passes .through filters r containing asbestos or othersuitable material and also throu h two or three sheets of wire gauze.The i tere are preferably .contained within the' easing m so as to bekept warm; this will prevent an tendency to condense the petrol that mae present. Naturally the material emp oyed in the filter must not besuch.as

would absorb or combine with the petrol. The air emerges from theapparatus through sheets of gauze and then by tubes s which are bent soas to prevent( any obstacle thrust into them as seen in Fig. 2.Alternativel a single tube may conduct the air from t ie casing as inFig. 4 and this tube may terminate in a suitable U-tube or the ne y -tected by guards 8 pivote like containinv suitable non-volatile liquid lsuch as high flash-point oil'or a mixture of glycerin and water throughwhich the air bubbles. Such a cvice serves to indicate whether the pumpis in working order and the air circulating properly, but should bc soarranged that it docs not introduce a great back-pressure suc-h as tohinder the assagc ofthe air. The object of the gauze s ieets is mainlyto prevent an ex losion or ignition of gas inthe instrument rom passingto the outside. l

It will be obvious that with an apparatus of this nature it is essentialto take precalitions against the inflammable gases which may be resentbeing ignited by sparks or the like rom the apparatus itself, For thispurpose the whole of the apparatus is inclosed and means are provide forinsuring that the switches controlling the variable circuits shall bebroken before any part of the s paratus can be opened. Thus in iront oftige tubes l. l is a door t supported on hinges u. This door is normallyheld closed by a bar 'v'andilugs w attached to a vertical rod-z. The rod'v and the lugs w press the door tightly down againstan india rubber orotlpr strip on the inside so as to make it airt. tlg'lwo plates'y arearranged to fold over the door one covering the spring catclrby whichthe bar v is engaged. These plates are attached to verticalrod-s 'zwhich ass up to the casin 2 above. Just within t iis casing are Switc es3, 3, shown' in Fig. 1 and the contact pieces of these switches areattached to the vertical rods z'so. that when the plates are turnedaside. to allow the vopening of the doort the switches. 3, 3 areopenedf. To the rods-z are also'attaclied guards 4 which cover the-lampsc inisiich away that neither of these lags can be. removed to bereplaced by aA fr one until its guard is turned aside and thus itsswitch opened. Similarprovisions am made for shutting up the casing 2,there being a bai: 5 as before stretched across the door and mountedupon a rod; 6 with lugs 7.

Extensionsfrom the guards 4 cover the end cf the rod 5 or rather thespring catch which engages it, in order to insure the switches 3, 3,bein opened beforethe casing 2 can be opened. he lamps g are also prouon a rod 9 whichcarries a projection 10 a apted toengage with the metalpiece 11 upon the axle of the main switch 12. Thus. if either of theselamps has to be removed its guard has first to be turned aside 'and themain switch opened. Moreover the switch cannot again be closed until theguards are in their proper positions. i

It will be evident that the type of detector device may be considerablymodified andA still serve t apurpose of the invention. The

. proceeding.

indication may be given by any other change in t-lic physical propertiesof the wire resulting from the heating. What we claim is:-

l'. In an apparatus for the detection of' combustible gases, thecombination of a catalytic agent and means for heating same,v

'said resistances, indicating lamps, connections between said lamps anda source of electric supply, an armature operated by said l rola andmeans for causing said armature to s iort circuit one of said lamps,with a system of pipes and means for drawing gases through said pipesand passing them over'tlie catalytic agent.

2. In an apparatus for the detection of combustible gases, thevcombination of a catalytic agent and means for heating the same, asystem of pipes, means for drawing gases through said pipes and passinthem over the catal ticv avent, electrical devices adapted to beeiiecteda by the catalytic action of said agent,l with casings andguards for protecting said devices, a source of electrical power,circuits including said source and the electrical devices, switc es insaid circuits adapted on opening to separate respective devices from thesource of power, and means for effecting the opening of said switches'when the protection of their respective devices is disturbed. 4 y

3. In an apparatus for the detection of combustible gases,thecoinbination with parvaried by catalytic action; a relay with twoparallel coils each' in series with one of said resistances, indicatinglamps, asource of supply, connections between said lamps and a source ofsupply an armature operated'by said relay and ,means for causing saidarma.- ture to short circuit one of said lamp sistances and lamps,"switches arranged in the circuits of said resistances and lamps, and

mechanical connections betweenthe switches whereby any' and the guardsand casin switch 1s o cned upon the disturbance of the corres on ingprotective device.

n an apparatus for tho-detection of combustible gases, the combinationwith a catalytic ent, means for heating sameA and means for emonstrstingthel activity of 'said agent, of apparatus for causing the air to betested to pass over the catal tcagent, a U- tube arranged to form parto?, the path ofthe air and a non-volatile liquid in s-aid tubothrouglrwhich the air bubbles, whereby an indication is given thatcirculation of air is 5. In an apparatus for the detection ofcombustible gases, the combination of a catas of: guards and casings forprotecting sa1dre' yv allel electrical resistances one adapted to be vlytic agent and means for heating same, elecincluding the electricaldevices, switches inA sai-il circuits, and connections between saidswitches and the guards whereby any switch is opened when `thecorresponding guard is removed.

6. In an apparatus for the detection of' combustible gases, thecombination with a catalytic avent, means for heating same and means fori einonstrating the activity of said agent, of apparatus for causing theair to`be tested to pass over the catal tic agent, a vessel ada )ted tocontain liquii arranged in the path ci .the air passing from saidcatalytic agent, and a non-volatile liquid in said vessel through whichthe air must pass, whereby an indication is given that circulation ofair is proceeding. i

. 7. In an apparatus for the detection of combustible gases, thecombination of a catalytic agent, means r heating .same and means fordemonstrating the activity of said avent, with apparatus for causing theair to be tested to pass ovelz the catalytic `agent, a filter containingl`-frriaterial which neither evolves nor absorbs, "combustible gasesarranged in the path of th air proceeding to the catalytic device, atube in the path of the air leading to thc cata t ic:device andanon-volatile liquid in said tubeto give an indication that circulationof airis-prof 'ceedi:rig.

8. In an4 apparatus for the detection of combustible gases,- thecombination ofxa catalytic a ent and means for heating same,

' electrical r evices for demonstrating the ac- V varied by catalyticaction, means tivity of said agent, with a system of pipes, means fordrawing gases through said pipes, and passing them over thecatalytic'agent, a filter containin material which neither evolves norabsois combustible gases arranged in the path of the air proceedin tothe catalytic agent, a U-tube in the path of theair leading to thecatalytic agent, and ii i non-volatile liquid 4in said tubeto give anindication that lcirculation of ail-,is proceeding.

9. In an apparatus for the detection of combustible gases, thecombination of paraL icl electrical conductors one adapted to be or suplying air to the apparatus, means for cata ytically efl'ccting thecombustion of inflammable material contained in said air, a relay withtwo parallel coils cach in series with one of said conductors,indicating lamps, a source of electric sup ly and connections betweensaid source and) the lamps, means control-led by a relay for shortcircuiting one of the lamps, switches in the circuits of the lamps andconductors, guards for protecting said lamps and conductors, connectionsbetween said switches and the guards whereby each switch is opened vwhenthe corresponding gua-rd is moved, with a device for filtering the air sup lied to the apparatus through a. material wiiich neither evolves norabsorbs combustible gases, a'U-tube in the ath of the air lcadinv to theapparatus, am a nonvolatile liqiiidain said tube to give an indicationthat circulation of airis roccedin 10. In an apparatus for tie detectionof combustible ases, the combination of two electrical concuctors ofcatalytically active material, a source of electrical power, connectionsbetween -said conductors and the source whereb the former are adapted toreceive in para lel a current which heats them, means for indicatin thefurther heating through catalytic ac t on',A tubes inclosing saidconductors, a casing to contain said tubes, and easily removable catchesto hohl the tubes with means for supplying air to the casing andpassages in the casing adapted to allow the air to pass through one tubebut only around the other.

11. In an apparatus for the detection of combustible gases, thecombination of two electrical conductors of catalytically activematerial, means for heating said conductors,'

means for indicating their further heating through catalytic action,easily removable tubes inclosing said conductors, a casing to containsaid tubes with passages allowin air to pass through one tube but onlyarouni the other, with means for supplying air to the casing, a filterin the path of the air proceeding to the casin and a device in the pathof the air leaving tlhe casing for indicating that circulation isproceeding.

In witness -whereof we have signed our names to' this specification ,inthe presence of two subscribing witnesses.

' ARNOLD PHILIP, l Louis J. STEELE.

Witnesses:

HUBERT A. Giu., LEONARD E. HinjNEs.

as.k

